<!--
 * @Description: 
 * @Author: 赵渝航
 * @Date: 2021-03-04 11:22:50
 * @LastEditTime: 2021-03-04 15:26:34
 * @LastEditors: Please set LastEditors
-->
<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>


  <style>
    .content {
      float: left;
      width: 100%;
    }
    .main {
      height: 200px;
      margin-left: 110px;
      margin-right: 220px;
      background: green;
    }
    .main::after {
      content: '';
      display: block;
      font-size:0;
      height: 0;
      zoom: 1;
      clear: both;
    }
    .left {
      float:left;
      height: 200px;
      width: 100px;
      margin-left: -100%;
      background: red;
    }
    .right {
      float: right;
      height: 200px;
      width: 200px;
      margin-left: -200px;
      background: blue;
    }
  </style>


</head>
<body>

  <div class="content">
    <div class="main"></div>
  </div>
  <div class="left"></div>
  <div class="right"></div>
</body>
</html>

